All at a whopping pace of 4 transactions per second... Which means that if the entire population of Denver used Bitcoin, they'd only get to make a single transaction once every 2 days.
I don't care what you say or what you compare it to, Bitcoin is very inefficient at what it does. And worse, its energy consumption is not a function of its transaction volume, but of its price in fiat. The higher the price, the more energy miners will throw at it as they attempt to win the next block reward.
And it is this way by design. Take all that inefficiency away and you give up all that makes Bitcoin what it is....
source: https://www.wolframalpha.com/input/?i=(population+of+denver)...